Had to hunt this for the logo alone. Built by MailChimp (impressed by how they've expanded their portfolio of products beyond email mktg).
Solid tool for brands to reply directly on Twitter. Lately, I've noticed a ubiquitous trend of people not wanting to DM brands or switch to email, preferring to handle issues or raise concerns publicly on their timeline. 140 characters is definitely not enough for that type of interaction, LongReads and their adorable logo nail it.
